24.7 Tracing EL Expressions

EL is not well supported with exceptions to inform you of specific failures. However, Example 24-7 shows one common exception you are likely to see when the resolver is unable to completely evaluate the expression.

Example 24-7 Expression Evaluation PropertyNotFound Exception

javax.faces.el.PropertyNotFoundException:
   Error setting property 'resultsTable' in bean of type null
at com.sun.faces.el.PropertyResolverImpl.setValue
   (PropertyResolverImpl.java:153)

You can check your web page's source code for problems in the expression, such as mistyped property names. When no obvious error is found, you will want to configure the logging.properties file in the <JDeveloper_Install>/jre/lib directory to display messages from the EL resolver.

To trace EL expression variables:

1. Open <JDeveloper_Install>/jre/lib/logging.properties in your text editor.

2. Set java.util.logging.ConsoleHandler.level=FINE.

3. Add the line:

   com.sun.faces.level=FINE

4. Run your application and view the variable resolution in the JDeveloper Log window.